1. Field of the Invention
The present invention relates to radio frequency IC devices, and, more particularly, to a radio frequency IC device including a radio frequency IC chip used in an RFID (Radio Frequency Identification) system and an electronic apparatus including the radio frequency IC device.
2. Description of the Related Art
Recently, an RFID system has been developed as a product management system in which a reader/writer arranged to generate an induction field communicates with an IC chip (hereinafter also referred to as an IC tag or a radio frequency IC chip) attached to a product or a case in a non-contact manner so as to obtain predetermined information stored in the IC chip.
Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 11-515094 discloses an RFID tag including an IC chip mounted on the main surface of a printed circuit board and an antenna provided in the printed circuit board. In this RFID tag, the antenna and the IC chip are electrically connected to each other. The miniaturization of the RFID tag is achieved by providing the antenna in the printed circuit board.
However, the number of manufacturing processes required to produce the RFID tag is increased in order to prepare the dedicated antenna, and a space is required for the dedicated antenna. This leads to increases in the manufacturing cost and size of the RFID tag. As illustrated in FIG. 2 in Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 11-515094, the number of manufacturing processes is increased especially if an antenna having a meander shape is formed, since internal electrodes included in a plurality of layers must be processed. Furthermore, in order to achieve the impedance matching between the IC chip and the antenna, a matching section is required. If the matching section is disposed between the antenna and the IC chip, the size of the antenna is increased. Furthermore, if the IC chip is modified, the shape of the antenna must be changed.